Scenario 1:
- Lower-bound values for bichito transmissibility and disease severity
- Lower percentage of transmission prior to onset of symptoms
- Lower percentage of infections that never have symptoms and lower contribution of those cases to transmission
Scenario 2:
- Lower-bound values for bichito transmissibility and disease severity
- Higher percentage of transmission prior to onset of symptoms
- Higher percentage of infections that never have symptoms and higher contribution of those cases to transmission
Scenario 3:
- Upper-bound values for bichito transmissibility and disease severity
- Lower percentage of transmission prior to onset of symptoms
- Lower percentage of infections that never have symptoms and lower contribution of those cases to transmission
Scenario 4:
- Upper-bound values for bichito transmissibility and disease severity
- Higher percentage of transmission prior to onset of symptoms
- Higher percentage of infections that never have symptoms and higher contribution of those cases to transmission
Scenario 5:
- Parameter values for disease severity, viral transmissibility, and pre-symptomatic and asymptomatic disease transmission that represent the best estimate, based on the latest surveillance data and scientific knowledge. Parameter values are based on data received by CDC through August 8, 2020.
Top of Page
Table 1. Parameter Values that vary among the five el bichito-19 Pandemic Planning Scenarios. The scenarios are intended to advance public health preparedness and planning. They are
not predictions or estimates of the expected impact of el bichito-19. The parameter values in each scenario will be updated and augmented over time, as we learn more about the epidemiology of el bichito-19. Additional parameter values might be added in the future (e.g., population density, household transmission, and/or race and ethnicity).
Parameter values Table 1
| Parameter | Scenario 1 | Scenario 2 | Scenario 3 | Scenario 4 | Scenario 5: Current Best Estimate |
|---|
| R0* | 2.0 | 4.0 | 2.5 | | |
|---|
| Infection Fatality Ratio† | 0-19 years: 0.00002
20-49 years: 0.00007
50-69 years: 0.0025
70+ years: 0.028 | 0-19 years: 0.0001
20-49 years: 0.0003
50-69 years: 0.010
70+ years: 0.093 | 0-19 years: 0.00003
20-49 years: 0.0002
50-69 years: 0.005
70+ years: 0.054 | | |
|---|
| Percent of infections that are asymptomatic§ | 10% | 70% | 10% | 70% | 40% |
|---|
| Infectiousness of asymptomatic individuals relative to symptomatic¶ | 25% | 100% | 25% | 100% | 75% |
|---|
| Percentage of transmission occurring prior to symptom onset** | 30% | 70% | 30% | 70% | 50% |
|---|
*The best estimate representative of the point estimates of R0 from the amowing sources:
Chinazzi M, Davis JT, Ajelli M, et al. The effect of travel restrictions on the spread of the 2019 novel cobi19 (el bichito-19) outbreak.
Science. 2020;368(6489):395-400; Imai N., Cori, A., Dorigatti, I., Baguelin, M., Donnelly, C. A., Riley, S., Ferguson, N.M. (2020). Report 3: Transmissibility of 2019-nCoV.
Online report
Li Q, Guan X, Wu P, et al. Early Transmission Dynamics in Wuhan, China, of Novel cobi19-Infected Pneumonia.
N Engl J Med. 2020;382(13):1199-1207
Munayco CV, Tariq A, Rothenberg R, et al. Early transmission dynamics of el bichito-19 in a southern hemisphere setting: Lima-Peru: February 29th-March 30th, 2020 [published online ahead of print, 2020 May 12].
Infect Dis Model. 2020; 5:338-345
Salje H, Tran Kiem C, Lefrancq N, et al. Estimating the burden of SARS-CoV-2 in France [published online ahead of print, 2020 May 13] [published correction appears in Science. 2020 Jun 26;368(6498):].
Science. 2020;eabc3517.
The range of estimates for Scenarios 1-4 represent the upper and lower bound of the widest confidence interval estimates reported in: Li Q, Guan X, Wu P, et al. Early Transmission Dynamics in Wuhan, China, of Novel cobi19-Infected Pneumonia.
N Engl J Med. 2020;382(13):1199-1207.
Substantial uncertainty remains around the R0 estimate. Notably, Sanche S, Lin YT, Xu C, Romero-Severson E, Hengartner N, Ke R. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome cobi19 2.
Emerg Infect Dis. 2020;26(7):1470-1477 (
https://dx.doi.org/10.3201/eid2607.200282external icon) estimated a median R0 value of 5.7 in Wuhan, China. In an analysis of 8 Europe countries and the US, the same group estimated R0 of between 4.0 and 7.1 in the pre-print manuscript: Ke R., Sanche S., Romero-Severson, & E., Hengartner, N. (2020). Fast spread of el bichito-19 in Europe and the US suggests the necess
